medwireNews: Research from Belgium indicates that a substantial proportion of those who have occupational asthma (OA) related to cleaning agents have specific airway sensitivity to the components of detergents.

It was previously assumed that the ability of such products to induce asthma symptoms was mostly related to their irritant effects.

But the study authors, Olivier Vandenplas (Universite Catholique de Louvain, Yvoir) and colleagues, found that quaternary ammonium compounds (QACs) – found in disinfectants, surfactants, and shampoos –were the most common culprit, inducing decreased lung function, increased sputum eosinophils, and airway hyperresponsiveness after exposure.

“The findings of this study may help to improve the diagnosis, management and prevention of cleaning-related asthma, although further investigation is required to identify the underlying pathophysiological mechanisms,” the authors comment, writing in BMJ Open.

The team retrospectively analyzed the results of specific inhalation challenges (SICs) carried out at a single center on 44 workers with symptoms of OA related to cleaning agents and/or disinfectants.

Overall, 17 (39%) had a positive SIC result – a decrease in forced expiratory volume in 1 second (FEV1) of at least 20% – on exposure to cleaning agents or disinfectants used at work.

Ten (59%) of these positive results were observed using agents that contained QACs, while three (18%) were related to glutaraldehyde exposure, and one (6%) to both agents. Two (12%) further participants responded to ethanolamines.

And, supporting a specific hypersensitivity mechanism behind these results, 11 (65%) positive SICs were associated with a significant increase in postchallenge airway hyperresponsiveness – measured as the histamine concentration required to provoke a 20% fall in FEV1, a greater than 2% increase in sputum eosinophils, or both of these outcomes.

In particular, this was true for nine of the 10 participants who had a positive SIC in response to QACs.

The authors also note that over the course of their study, from 1992 to 2011, there was a significant increase in the percentage of SIC procedures requested due to possible OA related to cleaning products, with most positive cases identified in the most recent decade.

This yields “some suggestion as to a recent increase in OA caused by cleaning/disinfection materials,” they comment.